This invention relates to the production of a chemically treated heat producing fiber, and more particularly, to the production of a intercalated graphite fiber useful as an infrared decoy or screen for protection of military targets from ordnance equipped with infrared heat-seeking detectors.
With the advent of the electronic age, modern warfare has become increasingly more and more based on complex electronic equipment. One particular group of electronic devices are the heat seeking missiles and airborne ordnance which "home in" on their desired targets by being inexorably drawn to the infrared radiation emitted by them. In most instances, the radiation emitted is generated by the engine of the target, i.e., the power plant on a warship, or an airplane's jet engines, for example. As modern electronic equipment becomes more and more sophisticated, these heat seeking weapons are becoming increasingly more accurate and difficult to avoid.
One attempt to negate these heat-seeking ordnances' effectiveness is the growth of the art of producing suitable heat generating "clouds" known as infrared emissive chaff, to function as a heat-emitting decoy which attempts to confuse the infrared seeking weapon from finding its desired target. However, designing a suitable infrared chaff has been a great problem in the art since such materials must measure up to several stringent requirements.
Materials which have been used as infrared chaff have included the following:
A. The class of solid pyrophorics which consists of finely divided solids such as white phosphorus and lithium hydroxide, and which react, upon initial exposure to the atmosphere, with the liberation of intense amounts of heat. However, these materials are extremely hazardous to store, and more seriously, produce an intense heat which lasts for but a few seconds, whereas a desirable infrared chaff should produce a moderate heat source lasting at least thirty seconds or more.
B. Eutectic chaffs, such as solids like barium hydroxide, undergo a phase transition near ambient temperatures, with the resulting liberation of heat. However, these materials have the draw-back that the quantity of heat liberated per unit weight of material is insufficient for the desired use.
C. Pyrophorics which are dissolved in a solvent and then applied as a solution on an absorptive solid such as paper or a textile fiber. Suitable materials are the trialkylaluminums and the organosilanes, and they can be diluted to the extent of providing a measure of control over the pyrophoricity of the resultant chaff. However, these materials are hazardous to handle, decompose during storage, and are also hampered in their effective dispersal into the atmosphere by the capillary forces of the liquid solvent.
It is, accordingly, an object of the present invention to provide an infrared chaff that supplies a suitable amount of heat for up to one minute duration, and ameliorates the hazards inherent in storage of the material.
It is a further object of the invention to produce an infrared chaff which does not decompose during storage, can be designed to give off heat and radiation of a desired temperature, and further functions as a radar and radio-frequency reflective chaff.
These and other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention.